That's more than the 34,000 killed by guns and the 34,000 killed by car crashes, reports German Lopez of Vox. It's even more than the 42,000 people who died at the height of the HIV/AIDS epidemic in 1995.

Illegal drugs aren't the culprit here, he says; it's prescription opioid painkillers, like OxyContin, Percocet, and Vicodin, which create dependencies and often lead to heroin use.

According to research published in a 2014 issue of the Journal of the American Medical Association, states that legalized medical marijuana saw a significant drop (24.8 percent) in overdoses, resulting in 1,729 fewer deaths in 2010 alone.

Keller notes that while researchers couldn't say that legalizing weed caused the decline in deaths, other research shows a correlation between an increase in marijuana dispensaries with a decrease in opioid addiction.

When we spoke with Jahan Marcu, chief scientist for the marijuana advocacy group Americans for Safe Access, he was careful to note that the biggest results have been seen in combining cannabis with opioid treatment.

"People given opiates and thc can be given 1/4 the opiate dose and get the same pain relief," he told Tech Insider.

"When you consume cannabis, your body thinks it's fat," he explained. "This is thought to be why your body doesn't get addicted to cannabis often. Other molecules can take advantage with this — opiates will be trafficked into fat with cannabinoids."

So, he says, medical marijuana can lead to lower doses of opioids, lowering the chance of addiction.